**2.6.3 Bingham model**

The Bingham model (Eq. 7) describes the flow curve of a material with a yield stress and a constant viscosity at stresses above the yield stress (i.e. a pseudo-Newtonian fluid behaviour; Seyssiecq & Ferasse, 2003). The yield stress (0) is the shear stress () at shear rate () zero and the viscosity () is the slope of the curve at stresses above the yield stress.

$$
\pi = \pi\_0 + \eta \,\,\,\,\,\gamma \tag{7}
$$

0 = 0 Newtonian behaviour 0 > 1 Bingham plastic behaviour
